Field of the Invention
The present invention relates to data storage devices and operating methods of a FLASH memory, and in particular, relates to data storage technology for a FLASH memory.
Description of the Related Art
FLASH memory is a non-volatile memory for data storage, which is electronically erased and programmed.
NAND FLASH is a type of FLASH memory, mostly implemented in a memory card, a USB FLASH device, a solid-state device (SSD) and so on.
A storage array of a NAND FLASH includes a plurality of blocks. An erase operation should be performed on an entire block. To release the space of a used block as a spare space to be allocated later, the whole space of the used block has to be erased. Valid data scattered throughout several blocks should be collected to other blocks (by performing a garbage collection operation). Only invalid data is left in the several blocks. The blocks containing only invalid data can be erased and then regarded as spare blocks.
The garbage collection operation, conventionally, consumes a considerable amount of computing resources. A method for efficiently operating the storage array of a FLASH memory is desirable in the field.